Speaking of lightning, a way o determine how far away lightning strikes it to count the number of seconds between the lightning and the thunder and divided by 5. Why does this work?
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cielo
ANSWERS: 3
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Because of the relation between the speed of light vs the speed of sound.
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Sound travels at 1128 ft/s. Light travels at 983,571,056 ft/s. So, for the all intents and purposes, you see the lightning as soon as it occurs, but it will take the thunder some time to reach you depending on how far away it is. If it takes the sound 5 seconds to reach you, then the lightning is actually about 5,640 ft. away. So, it is actually a little over five miles away.
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The delay between when you see lightning and when you hear thunder occurs because sound travels much, much more slowly than light. Sound travels through air at about 1100-1200 feet (330-350 meters) per second (depending on altitude, relative humidity, pressure, etc.), which is a little more than one mile per five seconds (one kilometer per three seconds). In comparison, the speed of light is 983,571,058 feet (299,792,458 meters) per second. For example, if lightning strikes a point 1 mile away, you will see the strike approximately .00000536 seconds after the strike while you will hear it approximately 4.72 seconds after the actual strike. If you calculate the difference between these two experiences, a person will hear a strike approximately 4.71999 seconds after the strike actually occurred. Therefore, 5 seconds per mile is a fairly robust approximation.
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